Telephone-transmitter.



I F. GO'HSCHAL-K.v

TELEPHONE TRANSMITTER.

APPLICATION FILED I'EB. 10, 1912.

Patented Dec. 3, 1912.

2 SHEETS-SHEET 1.

7 .w n m m M. E S T m G F P. GOTTSOHALK. TELEPHONE TRANSMITTER.

APPLICATION IILED FEB. 10, 1912.

masgwa Patented Dec. 3, 1912.

2 SHEETS-SHEET 8.

is hill-Si FELIX GOTTSCHALK, 0F NEW-3503K, N. Y.

TELEPHDhlE-TRANSMETTER.

Specification of Letters Patent.

1 causes.

Patented Bee. 3. i912.

Application filed February 10, 1912. Serial No. 676,50?

To all whom it may concern:

Be it known that I, FELIX Gorrsoirsmr, a citizen of the United States,residing at blew York, in the count-y of New York and I State of NewYork, have invented certain new and useful improvements inTelephoneiransmitters, of which the following is a specification,reference being had to the accompanying drawing.

lily invention relates to telephone transmitters and consists of animproved construction whereby the interior of the instrument is made airand water tight, the usual forwardly projectingv mputlrpiece iselimihated, and a more simple and eflicient structure secured thanheretofore. There are other advantages which are hereinafter describedand claimed.

ln the accompanying drawings Figure 1, represents a plan view of thetransmitter embodying this invention, a portion of the guard beingremoved in order to show a portion of the interior construction. Fig.2,-is acenlral sectional view through the transmitter. the diaphragmbeing shown only partly in section. Fig. 3. is a detail. of the terminalpiece used in the transmitter shown in. these drawings. Fig. 4, is adetail of the diaphragm used, showing a spider member connected thereto,and Fig. 5, is a detail ofthc filler block and the holding ring used inthis transmitter.

Similar reference characters refer to similar parts throughout thedrawings.

1 is a ring forming an internally threaded casing, the sound receivingdiaphragm '2 is placed acrossthe front of this casing, and a piece ofsuitable packing 3, such as lead or semi-vulcanized rubber, is usedtoform an air-tight joint. The diaphragm is clamped to the casing by meansof the screws indicated at 4 and 5. a suitable number of which aredisposed through the clamping ring 6. After the diaphragm is secured inposition the filler block 7 is screwed into the casing, and the annularrib 8 forces the diaphragm outwardly, thereby tauting or stretching samein a very perfect manner. It is obvious that other means can be usedbesides the thread, as shown, tohold the filler block in placeforinstance screws passing through the casing and 'engaging the block;

Such modifications I deem within the scope of my invention; Thisstretched diaphragm E find to be much more etfic-ient'than the usualtype, it beingmore susceptible to the delicate sound vibrations Withouthaving annoying side tones.- This method of stretching eliminates thenecessity of dampingsprings, and the tiller block in addition forms awater-tight joint where it engages the diaphragm packing.

In the center of the filler block is a cham her just large enough tohold the cell 9 containing the variable resistance medium. This cell beof any well known type and constitutes that'portion of the transmitterthrough which an electric current must pass to be subjectedto varyingimpulses from the sound receiving diaphragm -2. The cell shown iu thedrawing is of a well known type having its insulated electrode towardthe diaphragm, and its frame elect-rode toward the rear of theinstrument, stem 10 being a part of the cell frame. l dy method ofmounting this stem in its support I consider to bee separate inventionand have embodied same in my application for Letters Patent fortransmitter casings, Serial No. 677,112, but I disclose, this method h-witis peculiarly adapted to this type of trans mit-ter although it isobvious that it may be used with other structures.

. The stem 10 is placed in the recessed terminal piece 11, which isinsulated from the casing 1 by packing shown at 1:2 and by suit ifs ablvhushed screws 13 and 14. -TI18 stem secured in place by the adjustentscrew 15, and to prevent the ingress of moisture or air'l-provide thepacking 16 and screw 17, thereby closing the opening above 15. At 18 isshown the connecting-cord or wire which is held in the terminal piece bysuit.- able means such as the screw 19.

The front electrode is connected to the diaphragm by means of a spider20, having two or more legs, the outer ends of which touch the diaphragmat int-erperipheral points. i find increased efiiciency is obtained byplacing' the spider legs one-third the distance from the center to theedge of the diaphragm, although the best position diiiers with thediaphragm-thickness and determined by experiment. The spider may besecured to the diaphragm, or may simply pressed against it.

To provide means for mounting the trans- .mitter on the telephoneinstrument I provide'the usual back-shell 21, and induce t front of theinstrument with the gua'rd Q2, having suitable apertures through it topermit the sound waves to impinge onthe diaphragmn. This guard is soshaped that it iaps over the back shell as shown, thereby permitting thesame screws 23 and 24 to hold guard, back shell, and transmittertogether, thus eliminating all but one joint or seam (at 25) on theoutside of the instrument.

I also provide a hole 26 at the bottom of the guard to drain any salivaor other moisture that may collect in the front of the into the frontcell electrode, through the variable resistance medium to the rearelectrode, to the cell stem 10, to terminal piece ll and to the circuitconnection 18; and it will be observed that the interior of theinstrument is atall times efi'ectually sealed, thereby permitting thecircuit wire to be attached or the cell adjusted without danger ofpermit-ting the entrance of nioistureso fatal to the cell and otherinterior parts.

Owing to the efliciency of a transmitter constructed in this manner, theusual flaring mouthpiece is unnecessary, and the sanitary and easilycleansed guard as shown ma; be used. The entire instrument may beplunged in any germicide solution without injury, as the interior is notonly moisturethe adjustment of proof, but all air chambers areeliminated by the filler block, and therefore the small amount of airconfined in the interior cannot expand or contract sutficiently toafl'ect the instrument. I'claim: 1. In a telephone transmitter, acasing, a metallic diaphragm on said casing, a clamp ring on saiddiaphragm, means for holding said casing rinlgand diaphragm together toform awatertight joint between thediaphragm and casing, a resistancecell means for connecting said cell with said diaphragm at two or moreinterperipheral points, and a'filler block adapted to stretch saiddiaphragm outwardly against said ring.

2. In a telephone transmitter, a metallic diaphragm, a casing, means forholding said diaphragm at all points of its periphery to thecasing,means for stretching said diahragm outwardly from said casing, apertorated guard over said diaphragm, an insulated back-plate over saidstretching means, and transmitter mechanism inclosed in the chamberformed by the diaphragm casing and back-plate.

3. In a telephone transmitter, a perforated metallic guard, a drain holeat the bottom of said guard, a metallic diaphragm back of said guard, acasing supporting said diaphragm, internal threads on the casing, afillerblock having a. threaded edge engaging the threads in said casing,an aperture in said filler block, transmitter mechanism in saidaperture, and a supporting member for said cell forming a closure forsaid aperture.

4. In a telephone transmitter, a metalhc diaphragm secured at itsperiphery to a casing, water-tight'means interposed between saiddiaphragm and the casing, a transmitter cell within said casing and.inclosed by said casing, a terminal in electrical connection with oneside 'ofthe circuitpf said cell, a back shell covering the rear of saidcasing, a guard covering the front of said casing and overlapping saidbacltshell, and means. for holding the casing back-shell-Iand guardtogether.

In testimony whereof I hereunto aflix my signature in' the presence oftwo Witnesses.

FELIX GOTTSCHALK.

Witnesses I H. G. TORREY,

' CHARLES T YLOR.

